1. Field of the Invention
The present invention relates to a building management system and an operating method thereof, and more particularly to a building management system and an operating method thereof, wherein a multi-air conditioner system can be integrally controlled by a building management system (BMS) controller of a local operating network (e.g., LONWORKS) without modification of a network structure of the multi-air conditioner system based on an RS-485 communication scheme.
2. Description of the Related Art
Corresponding to equipment modernization of buildings in recent years, a control system has become widespread that can automatically control various subsystems installed in the building such as power/lighting and fire/security subsystems. A building management system (BMS) has been actively developed that can integrally manage these subsystems.
FIGS. 1a and 1b are block diagrams illustrating the configurations of conventional building management systems.
The conventional building management system shown in FIG. 1a includes subsystems installed in the building such as lighting, power, and security subsystems, an air conditioner system 20 including a plurality of indoor and outdoor units, and a BMS controller 10 integrally controlling all subsystems including the air conditioner system.
In general, the building management system centrally controls each subsystem through the BMS controller 10 using LONWORKS network technology based on the local operating network (e.g., LONTALK) protocol.
LONWORKS network technology, where ‘Lon’ stands for Local Operating Network, is a communication scheme which enables lowest level devices such as sensors and actuators, and devices for communicating and monitoring/controlling functions to send and receive data according to the same protocol. This technology supports a master/slave or peer-to-peer connection between field devices and enables a distributed control sharing information needed for control.
In the building management system, each subsystem includes at least one Lon device 15 to analyze data received from the BMS controller 10 and to send data back to the BMS controller 10.
In particular, as shown in FIG. 1a, in the air conditioner system 20 including a plurality of indoor units, the Lon device 15 can be connected to each one of the indoor units or to a group of the indoor units.
In the building management system comprising the air conditioner system 20, each indoor unit is installed in an individual room of the building, in general. Hence, it takes a long time until data sent by the BMS controller 10 for separate control of an indoor unit reaches the Lon device taking charge of the indoor unit, and is analyzed and processed. Consequently, it is difficult to immediately control the operation of the indoor unit. Moreover, because the Lon device has to be connected to each indoor unit, the installation costs of the building management system rapidly rise as the number of indoor units that are to be integrally controlled by the building management system increases.
If a Lon device is connected to a group of indoor units to reduce the installation costs, there exists a problem in that it is difficult to separately control each member of the group because all indoor units connected to the same Lon device perform the same operation according to a control command received by the Lon device.
Namely, if a Lon device is connected to a predetermined group of indoor units, all of the indoor units of the group connected to the Lon device perform the same operation. Thus, it is difficult to obtain separate control of each indoor unit. If there is a temporary need to separately control some of the indoor units, each must be separately connected to a Lon device and then controlled. After the separate control, the connected Lon device must be removed. Consequently, there exists a problem of resource waste.
Moreover, as shown in FIG. 1b, if the air conditioner system is a multi-air conditioner system in which one outdoor unit is connected with multiple indoor units, and each outdoor unit is connected to a Lon device, then the outdoor unit and indoor units perform the same operation according to a command passed through the Lon device. Hence, it is difficult to separately control the outdoor unit and indoor units.